A diglycidylether of bisphenol A, DGEBA, base epoxy resin has been modified with several different types of poly(ether imide)s with the goal of increasing the toughness of this high Tg epoxy system. Initially, Ultem$\sp\circler $ 1000-1000 from GE was blended into Epon 828/DDS. Phase separated systems resulted with a 2.5-fold increase in the fracture energy over the neat epoxy resin (676 J/m$\sp2$ vs. 265 J/m$\sp2).$ As seen under the SEM, the included phase pulled out of the continuous phase, indicating poor adhesion between the two phases. Next an amine terminated poly(ether imide), ATPEI, of Mn equal to 8600 was reacted into the same epoxy resin system. There was no increase in the fracture energy with the addition of the ATPEI except at the 40 weight percent loading level. At this level, the fracture energy was comparable to that of the 40% Ultem$\sp\circler$/E828/DDS (700 J/m$\sp2).$ Phase separation was not observed in the TEM above 10 weight percent of the ATPEI in the E828/DDS. A mix of the Ultem$\sp\circler$ and the ATPEI were added to the epoxy resin with favorable results. Phase separation was present. Good adhesion between the phases was evident. And at 20 weight percent, the mixed PEI modified E828/DDS had a higher fracture energy than either of the other two systems investigated previously in this study (409 J/m$\sp2$ for the mix vs. 176 J/m$\sp2$ for the ATPEI and 353 J/m$\sp2$ for the Ultem$\sp\circler).$ Finally, an amine terminated poly(ether imide) with Mn equal to 25,500 was reacted into the same epoxy resin. The fracture energy at 20 weight percent was higher than any of the systems studied previously (451 J/m$\sp2$ vs. 409 J/m$\sp2$ for the mixed PEI modified system). Phase separated morphologies occurred at lower loading levels than anticipated-co-continuous at 20% and phase inverted at 30%. In all cases the Tg's remained above 200$\sp\circ$C.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-4910 |
| Date | 01 January 1995 |
| Creators | Athanasiou, Cynthia Dawn |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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